A frame of the racket used in tennis and the like is provided with a plurality of string holes through which strings are inserted, along the circumferential direction of the frame. Generally, the string is strung to the frame through a grommet having a plurality of tube sections and a base section that connects these tube sections. Then, the net-like hitting surface is formed by the strings strung to the frame.
Patent Literature 1 discloses a string protector having a through hole through which the string slides in a pressing direction to obtain a wide sweet area.